Show_Oracle_Users.rb

gistfile1.rb

#!/usr//bin/env ruby                

################################################################################
#
# Program Name: Show_Oracle_Users.rb
# Author:  Sean Stephenson
# Course:  CS151B
# Date:  2010-02-07
# Adapted From: oracle_in_ruby.rb AND ShowTables (both by Abbas)
#
# ShowUsers.rb will do the followings:
# 1. running ShowUsers without argument will display all users in sorted order
# 2. with -n and a regular expression as an argument, it will display total
#    number of users matched with the regular expression.
# 3. with a regular expression as an argument, will display all users matched
# 4. with -n as an argument, it will display the total number of users
#
#################################################################################




#*********************************do_oracle(sql)*********************************
def do_oracle(sql)
   sql.chop! if sql[-1] == ';'
   cmd = <<-EOJ
       sqlplus -S scott/tiger <<-EOF
          set echo off head off pagesize 0
          #{sql};
          set echo on head on pagesize 24
          quit
       EOF
   EOJ
   done = system(cmd)
   abort("access to Oracle failed\n") unless done
end



#**********************************numUsers**************************************
def numUsers
  print "total number of users: "
  do_oracle("select count(username) from all_users")
end



#*********************************regExDisplay(match)****************************
def regExDisplay(match)
  puts "users matching regexp: "
  str = "select distinct username from all_users 
         where regexp_like(username, '#{match}', 'i')
         order by username"
  do_oracle(str)
end



#*********************************regExCount(match)******************************
def regExCount(match)
  print "total users matching regexp: "
  str = "select count(username) from all_users 
         where regexp_like(username, '#{match}', 'i')"
  do_oracle(str)
end



# displays all users in sorted order
if ARGV[0] == nil
  do_oracle("select distinct username from all_users order by username")
end



# displays total number of users matched with regular expression
if ARGV[0] == '-n' && ARGV[1] =~ /\w/
  regExCount(ARGV[1])
  exit 0 #needed so we don't also display total users below
end



# displays all users matched by regular expression
if ARGV[0] =~ /\w/ && ARGV[0] != "-n"
  regExDisplay(ARGV[0])
end



# displays the total number of users
if ARGV[0] == "-n"
  numUsers
end



exit 0